Hitherto, a number of organic ruthenium compounds have been known as a starting compound when producing a ruthenium thin film or a ruthenium compound thin film by a chemical deposition method such as a CVD method (chemical vapor deposition method) and an ALD method (atomic layer deposition method). There is dodecacarbonyl triruthenium (hereinafter, referred to as DCR) represented by the following Formula as the compound under investigation for practical use in recent years among the organic ruthenium compounds.

DCR is a substance which is solid (orange crystal) at room temperature and has a melting point of 154 to 155° C. The utilization of DCR is expected from the reasons that DCR has a simple molecular structure including Ru and CO and can be deposited by only the thermal decomposition without the use of a reactant gas and thus there is an advantage that impurities such as hydrocarbons hardly remain in the deposited thin film and the production efficiency of thin film is not adversely affected by the specification adjustment of the raw material container or the appropriate process control even if it is a solid raw material.
As the method for producing DCR, a method is basic in which a ruthenium compound as the raw material is carbonylated with carbon monoxide. In addition, ruthenium chloride is often applied as the ruthenium compound of the raw material. Ruthenium chloride is the most inexpensive and easily available among various kinds of ruthenium compounds and widely used as a raw material for a number of ruthenium complexes other than DCR.
Moreover, as the method for producing DCR to use ruthenium chloride as the raw material, the simplest method is a method in which ruthenium chloride reacts in a carbon monoxide atmosphere at a high pressure (several tens to 100 MPa) (see Patent Document 1). In addition, a method is also known in which a metal such as zinc metal or a metal salt such as KOH and Na2CO3 are added into the reaction system for the purpose of lowering the reaction pressure and ruthenium chloride is carbonylated (see Patent Document 2 and Non Patent Documents 1 and 2).
Furthermore, a method is also known in which an intermediate is produced using ruthenium chloride as the starting material and this is then carbonylated. There is a method in which, for example, ruthenium acetylacetonate obtained by reacting ruthenium chloride with an acetylacetonato salt is produced as an intermediate and this intermediate is carbonylated (see Patent Document 3).